During the coming year, it is proposed to continue evaluation of the Leucocyte Adherence Inhibition (LAI) technique as a means for the detection and diagnosis of cancer in man. Additional analyses will be done and final statistical evaluation of the results will be made. An attempt will be made to quantify the assay by use of a range of antigen doses. This is now possible because an Image Analyzer is available to facilitate cell counting. Work will continue on establishing the role of HL-A restriction on antigen presentation in the LAI system. This is being done by HL-A typing individuals and families and using their cells either for antigen presentation or as responder cells. Antigens consist of keyhole limpet hemocyanin and extracts of osteosarcoma. The use of the latter may permit elucidation of some aspects of the immune response to tumors in human cancer.